The present invention is directed towards thermostats and more specifically to thermostats having microprocessors which operate on a battery.
Thermostats having battery-operated microprocessors have become increasingly popular. The microprocessor is used to operate energy management programs which make operation of an attached heating ventilating air conditioning (HVAC) system more efficient.
However, when the battery began to lose its charge, microprocessor operation became unpredictable. As an example, if the battery charge is low enough, the microprocessor may cause a heat lock on which could be dangerous to the elderly and infants.
While battery level check detectors in thermostats are known in the art, they usually require additional circuitry which increases the cost of each individual thermostat. In addition, most thermostats only have a single level battery check which produces an indication to the user that a problem exists. Lastly, merely providing an indication that the battery level is low may not be sufficient to prevent a heat lock on.